1. Field of the Invention
The present invention relates to an electron beam lithography technology, and, more specifically, to the use of an electron beam drift detection device and a suitable detection method.
2. Description of Related Art
With advancement in semiconductor technology, the downscaling of semiconductor devices, for example, devices assembled in personal computers and mobile communication devices becomes overwhelming. In addition, the wiring and the transistor size of semiconductor devices are scaled down to further enhance the integration of semiconductor devices. Therefore, lithography technology became very important. The known lithography technology mentioned previously includes the following steps: scanning a beam of electrons in a patterned fashion across a substrate surface covered with a film called the resist, exposing the resist and selectively removing exposed regions of the resist. The purpose of this is to create very small structures in the resist that can subsequently be transferred to the substrate material, often by etching.
It can be seen that an accurate and reliable lithography technology is needed because of a high demand for enhancing the integration of integrated circuits. Therefore, an electron beam lithography technology (such as e-beam) using the charged-particle beam has been developed because a conventional lithography technology cannot achieve more precise patterning.
However, it is well known that electron beam direct-write lithography has a common problem due to the electron beam position varying over time. This often affects the accuracy of lithography patterning, and thus affecting the image resolution of the entire semiconductor patterning. Additionally, when the electron beam is fixed at one point, the beam drift cannot be detected easily because of the charging effect. As a result, the signal of the backscattered electron detector or the secondary electron detector is inaccurate and the position of the signal cannot be measured completely.
Therefore, the desire to develop a low-cost, high-precision detection device for electron beam direct-write lithography system and a method for detecting the electron beam drift have become very important in order to overcome the problems encountered in known lithography technology